20% Ni 마르에이징강의 Nb 이 기계적 성질과 석출 현상에 미치는 영향

Abstract

20% Ni managing steels with and without Nb (0.5 w/o) were prepared in vacuum induction melting furnace, followed by hot working and heat treatments. The yield strength of the Nb-containing alloy was about 4% higher than that of Nb-free alloy under managed conditions. However, the charpy impact energy of Nb-containing alloy tested at room temperature was lower by 25%, compared with that of Nb-free alloy, under the managed condition. Precipitates phases formed in the Nb-free alloy were HCP Ni₃Ti(η) and FCC Ni₃(Ti, Al)(γ`), while in the Nb-containing alloy orthorhombic Ni₃Nb appeared in addition to the ηand γ`phases.